Unless otherwise indicated herein, the materials described in this section are not prior art to the claims herein and are not admitted to be prior art by inclusion in this section. Embodiments of the present disclosure generally relate to a vibration generating apparatus.
A vibration generating apparatus converts electrical energy into mechanical vibrations using the principle of electromagnetic force. The vibration generating apparatus may be mounted in, for example, mobile phones, and the like, to thereby be used for silently notifying a user of call reception by transferring vibrations. In accordance with the rapid growth in the market for mobile devices such as the mobile phones, and the like, and with the trend for the addition of functionality to mobile devices, such mobile devices may be relatively small and have high quality. The demand for development of a vibration generating apparatus having a new structure capable of overcoming disadvantages of existing vibration generating apparatuses and quality has been improved.
Further, as the release of smartphones, among other mobile phones has rapidly increased, a touchscreen scheme has been adopted for use therein, such that a vibration motor has been used in order to generate vibrations at the time a touchscreen is touched by a user. Examples of preferred performance of the vibrations associated with the touchscreen are as follows. First, since vibrations generated at the time a touchscreen is touched are generated frequently than vibrations generated at the time of call reception, an operational lifespan of a vibration generating apparatus may need to be increased. Second, in order to increase user satisfaction when a user feels vibrations when touching a touchscreen, a response speed of the vibrations may be increased in accordance with a touch speed of the touchscreen.
For example, a piezo haptic actuator may be used. Such a piezo haptic actuator may use a principle of an inverse piezoelectric effect in which displacement is generated when a voltage is applied to a piezo element, that is, a principle of allowing a weight of a mover to be moved by the generated displacement to generate vibrations.
The vibrator may have the following exemplary features. A bandwidth of a frequency capable of obtaining a predetermined level of vibrational force or more may be wide, such that stable vibration characteristics may be implemented. Vibrations having low and high frequencies rather than a single frequency in a predetermined frequency range may be variously used. In addition, since the vibrator may implement rapid operational response characteristics, haptic vibrations may be implemented in a mobile device such as a mobile phone, or the like.